ESTIMATING MEIOTIC EXCHANGE PATTERNS FROM RECOMBINATION DATA - AN APPLICATION TO HUMANS

We present analytical methods to estimate the recombinational history of chromosomes in a human population. Our analysis, similar to those u tilized in Drosophila, can be used to construct meiotic maps based upo n crossover frequencies observed in family data. We apply this method of exchange estimation to a population of paternally and maternally in herited chromosomes 21. The patterns of chromosomal exchange estimated by this type of analysis are comparable to those obtained by the more technically difficult method of cytologically counting chiasmata amon g human male meiotic events (sperm). This type of analysis can be appl ied to both male and female meiosis, circumventing many technical prob lems inherent to cytological counting. Moreover, the distribution of e xchange locations along a chromosome for each exchange type (i.e., sin gle, double, or triple exchanges) can be examined individually, an adv antage compared to examination of genetic maps that only provide a sum mary of these distributions. We discuss how this analysis can be used to examine various assumptions concerning meiotic exchange in humans a nd investigate properties of the analysis that contribute to the accur acy of the results.